Patent Application
20220020549
The present disclosure relates generally to switching devices, and more particularly to sensing properties associated with the switching devices. Switching devices are generally used throughout industrial, commercial, material handling, process and manufacturing settings, to mention only a few. As used herein, “switching device” is generally intended to describe any electromechanical switching device, such as mechanical switching devices (e.g., a contactor, a relay, latching relay, air break devices, and controlled atmosphere devices) or solid-state devices (e.g., a silicon-controlled rectifier (SCR)). More specifically, switching devices generally open to disconnect electric power from a load and close to connect electric power to the load. For example, switching devices may connect and disconnect three-phase electric power to an electric motor.
A latching switch may maintain a particular state (e.g., open or closed) independent of power supplied to the latching switch. However, the armature position of the latching switch can change based on a user's interaction (e.g., manual reset) with the latching switch. Regardless of the position (e.g., open or closed) of the armature of the latching switch, it may be desired to detect the position of the armature without physically examining the latching switch.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.
In one embodiment, a system may include an armature configured to move between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The system may also include a coil configured receive a current, such that the current conducting in the coil is configured to magnetize a core. The magnetized core may cause the armature to move from the first position to the second position. The system may also include a control system configured to detect a position of the armature based on an inductance of the coil.
In another embodiment, a method may include sending, via circuitry, a plurality of gate signals to a plurality of switches that may cause the plurality of switches to open. The plurality of switches may be part of an H-bridge circuit. The method also includes sending, via the circuitry, a first signal to a first switch, such that the first signal is configured to cause the first switch to close. The method may then involve sending, via the circuitry, a pulse-width modulated signal to a second switch that is part of the H-bridge circuit and measuring, via the circuitry, a current conducting via the first switch while the pulse-width modulated signal is provided to the second switch. The current corresponds to a state of an actuator coil.
In yet another embodiment, a circuit may include a plurality of switches that may be part of an H-bridge circuit and a coil that may magnetize a core of an actuator based on a current conducting in the coil. The circuit may also include a diode configured to couple to the coil, a resistor configured to couple to the diode, and a switch that may couple to the resistor. The switch may close and conduct the current received from the coil.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
As described above, switching devices are used in various implementations, such as industrial, commercial, material handling, manufacturing, power conversion, and/or power distribution, to connect and/or disconnect electric power from a load. For example, a number of switching devices may be used to control operations, monitor conditions, and perform other operations related to various equipment in an industrial automation system. As such, the switching devices may be used to coordinate operations across a number of devices
With the foregoing in mind, it should be noted that the open operation of the switching device generally depends on a coil current and a core flux of a coil that induces a magnetic field in the switching device. Some types of switching devices include a latching mechanism that enable the switching device to remain in a particular position (e.g., open or closed) regardless of whether power (e.g., coil current) is present on the switching device. The latching switching device, however, can change states when a user interacts with the latching switching device using a manual reset operation or the like. Often times, when the user resets the latching switching device, a control system or other remote monitoring system may not be aware of the state (e.g., open or closed) change of the latching switching device without the use of position sensors or other hardware components that monitor the position of an armature in the switching device. As such, the present embodiments disclosed herein are related to systems and methods for detecting the armature position of a switching device without the use of position sensor hardware. Additional details with regard to determining the armature position of an armature in a switching device will be described below with reference to
By way of introduction,
The latching solenoid 10 may also include a latching mechanism that causes the spring 18, the armature 20, or both to lock or latch into a fixed position. For example,
Based on the magnetic field induced by the current in the coil 14, the armature 20 may move between positions as shown in
The latching solenoid 10 may interface with a number of electrical components, such as low-voltage circuitry, a microcontroller/microprocessor, and the like. In addition, the button 22 may provide a physical component that a user may access to manually perform operations for the latching solenoid 10 regardless of the current present on the coil 14. By way of example, the button 22 may be a trip or reset button for overload products. For a number of overload products (e.g., overload relays.), power to the latching solenoid 10 may be lost when an overload/trip fault is present. In this condition, the button 22 may be used to maintain a state (e.g., latched or de-latched) of the latching solenoid 10 when left at rest, while allowing for user to be able to modify the position of the armature 20 when pressed independent of the power provided to the latching solenoid 10.
With this in mind, it should be noted that although the current in the coil 14 may cause the armature 20 to move into the latched position, the removal of the current in the coil 14 may not cause the armature 20 to move again since it is latched in a fixed position. That is, the latching mechanism that mechanically latches or holds the armature 20 in a particular position after the core magnetizes of the armature 20 magnetizes, thereby causing the armature 20 to change positions. Alternatively, the latching mechanism may also be configured to mechanically latch or hold the armature 20 in a particular position after the coil 14 demagnetizes and the armature 20 changes position. In any case, the latching mechanism may be released via manual interaction by a user, thereby causing the armature 20 to move positions. However, as discussed above, the change in the position of the armature 20 may not be detected by a control system or monitor system without the use of additional sensors that monitor the position of the armature 20. That is, the presence of current or the lack of the current in the coil 14 may not be indicative of whether the armature 20 is in the latched position. As such, the embodiments described herein may be used to detect the position of the armature 20 of the latching solenoid 10 without the use of additional sensors.
With this in mind,
In one embodiment, the armature position detection system 30 may include an armature position sensor circuit 36. The armature position sensor circuit 36 may generally monitor the inductance of the coil in the electromagnetic actuator 34 to sense the position of the armature 20. In some embodiments, the armature position sensor circuit 36 may provide a pulse-width-modulated signal to the coil of the electromagnetic actuator 34 and determine the position of the armature 20 based on electrical properties (e.g., inductance) of the electromagnetic actuator 34.
Keeping this in mind,
The H-bridge circuit 52 may be connected to an actuator coil 56, which may be part of the electromagnetic actuator 34. By way of operation, one side of the H-bridge circuit 52 may be used to trip or induce a magnetic field in the core of the electromagnetic actuator 34, and the other side of the H-bridge circuit 52 may be used to reset or remove the magnetic field in the core of the electromagnetic actuator 34. For example,
To reset the position of the armature 20, the opposite side of the H-bridge circuit 52 may be driven, as illustrated in
In both modes of operations depicted in
In addition to providing the read enable signal, the control system may provide a ping signal to the NMOS switch 66. The ping signal may be a pulse-width modulated signal that cycles between a high voltage value and a low voltage value over a period of time. For example, the pulse-width modulated signal may be a voltage signal provided at 20 kHz and a 10% duty cycle. To deactivate the operation of the H-bridge circuit 52, the control system may remove the solenoid trip signals and the solenoid reset signal from the NMOS switch 158, the NMOS switch 62, and the NMOS switch 64.
By providing the read enable signal (e.g., high signal) to the gate of the NMOS switch 70, the control system may cause the NMOS switch 70 to close thereby providing a current path to ground for the coil current conducting within the actuator coil 56. Since the ping signal consists of a pulse-width modulated signal, the coil current through the actuator coil 56 is pulsed through a resistive load (e.g., resistor 172) in the measurement circuit 54. Based on the voltage present at node 74 in the measurement circuit 54, a diode 76 may be used to rectify or convert the voltage into a digital signal that may be measured at output node 78. The voltage measured at the output node 78 is dependent on the inductance of the actuator coil 56. With this in mind, it should be noted that the position of the armature 20 is also dependent on the inductance of the actuator coil 56. As such, based on the detected voltage signal at the output node 78, the control system or any suitable computing device may detect the position (e.g., open or closed) of the armature 20. It should be noted that the diode 76 may be any suitable diode such as a Schottky diode, a Zener diode, or the like.
For instance,
At time t4, the measurement circuit 54 may be activated as described above with reference to
Although the different peak values may be difficult to determine based on the analog values measured at the node 74, the diode 76 may rectify the coil current received at the node 74 to produce digital values, as shown in
Although the preceding discussion of the operation of the example circuit 50 is detailed using NMOS switches and PMOS switches, it should be understood that any suitable switching technology (e.g., MOSFET, IGBT, BJT) may be employed to perform the operations of the circuit 50. Indeed, the NMOS switches can be changed to PMOS switches, and vice-versa, so long as the gate signals change accordingly. In any case, it should be noted that the switches illustrated in
With the foregoing in mind, the control system may remotely access or the electromagnetic actuator 34 to determine the position of the armature 20. Indeed, the remote detection of the position of the armature 20 may enable users to know the state of the electromagnetic actuator 34 regardless of whether a user has manually changed the state of the actuator. That is, the control system may leverage the inductance of the actuator coil 56 to remotely determine the position of the armature 20. In some embodiments, the control system may then update a visualization to be presented via a display, send a notification to another computing device, or perform any other suitable operation to provide an indication regarding the position of the armature 20. In some embodiments, the control system may determine whether the detected state of the armature 20 matches an expected state of the armature 20. If not, the control system may send solenoid trip or solenoid reset signals to respective gates of switches to cause the H-bridge circuit 52 to change state of the electromagnetic actuator 34 to match the expected state. In this way, the control system may remotely control the operation of the electromagnetic actuator 34, while also remotely detecting the position of the armature 20 without using additional hardware.
It should be noted that the gate signals may be provided via a control system or any suitable computing device. As such, the control system may include any suitable computing system, controller, or the like. By way of example, the control system may include a communication component, a processor, a memory, a storage, input/output (I/O) ports, a display, and the like. The communication component may be a wireless or wired communication component that may facilitate communication between different components within the industrial automation system, to the electromagnetic actuator 134, or the like.
The processor may be any type of computer processor or microprocessor capable of executing computer-executable code. The processor may also include multiple processors that may perform the operations described below. The memory and the storage may be any suitable articles of manufacture that can serve as media to store processor-executable code, data, or the like. These articles of manufacture may represent computer-readable media (e.g., any suitable form of memory or storage) that may store the processor-executable code used by the processor to perform the presently disclosed techniques. The memory and the storage may represent non-transitory computer-readable media (e.g., any suitable form of memory or storage) that may store the processor-executable code used by the processor to perform various techniques described herein. It should be noted that non-transitory merely indicates that the media is tangible and not a signal.
The I/O ports may be interfaces that may couple to other peripheral components such as input devices (e.g., keyboard, mouse), sensors, input/output (I/O) modules, and the like. The display may operate to depict visualizations associated with software or executable code being processed by the processor. In one embodiment, the display may be a touch display capable of receiving inputs from a user. The display may be any suitable type of display, such as a liquid crystal display (LCD), plasma display, or an organic light emitting diode (OLED) display, for example. Additionally, in one embodiment, the display may be provided in conjunction with a touch-sensitive mechanism (e.g., a touch screen) that may function as part of a control interface. It should be noted that the components described above with regard to the control system are exemplary components and the control system may include additional or fewer components as shown.
Technical effects of the embodiments described herein include providing the ability to remotely detect a position of an armature in an electromagnetic actuator without employing position sensing circuitry, such as optocouplers and the like. Indeed, the position of the armature may be detected remotely by providing a pulse-width modulated signal to the actuator coil and measuring a digital voltage output that changes based on the inductance of the actuator coil. In this way, present embodiments described herein may provide systems and methods for detecting the position of the armature without including additional sensing circuitry.
It should be noted that although certain embodiments described herein are described in the context or contacts that are part of a latching solenoid or relay device, it should be understood that the embodiments described herein may also be implemented in suitable contactors and other switching components. Moreover, it should be noted that each of the embodiments described in various subsections herein, may be implemented independently or in conjunction with various other embodiments detailed in different subsections to achieve more efficient (e.g., power, time) and predictable devices that may have a longer lifecycle. It should also be noted that while some embodiments described herein are detailed with reference to a particular relay device or contactor described in the specification, it should be understood that these descriptions are provided for the benefit of understanding how certain techniques are implemented. Indeed, the systems and methods described herein are not limited to the specific devices employed in the descriptions above.
While only certain features of the disclosure have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.
